Initial commit

2019-11-15 12:59:38 +01:00
parent 40a414d210
commit b880c3ccde
6814 changed files with 379441 additions and 0 deletions
@@ -0,0 +1,184 @@
+Implimentation of a list using a linked list with pointers
+
+#include <iostream.h>
+struct element {
+  int number;
+  element *next;
+  };
+
+/* the operators declared on the type list.*/
+void read(element *&list);
+void write(element *list);
+int length(element *list);
+int position(element *list, int num);
+void remove(element *&list,int position);
+void insert(element *&list,int new_num,int position);
+element *ele(element *list,int position);
+
+void add(int new_num,element *&list,element *this_el);
+
+void main()
+{
+
+  element *list,*p,*q;
+  int leng;
+
+  read(list);
+  write(list);
+  q = ele (list,3);
+  add (5,list,q);
+  write(list);
+  insert(list,10,2);
+  write(list);
+  remove(list,4);
+  write(list);
+  insert(list,12,1);
+  write(list);
+  leng = position(list,10);
+  cout<< " pos of 10 is " << leng <<endl;
+  cout<< " The length of the list is: " << length(list)<<endl;
+  cout<<endl;
+  ]
+}
+/* reading a list from input */
+void read(element *&list)
+{
+  element *p,*last;
+  list = new element;
+  p = list;
+  cout<< " enter a number";
+  cin>>p->number;
+  while (!cin.eof())
+  {
+    p->next = new element;
+    last = p;
+    p = p->next;
+    cout<< " enter a number ";
+    cin>>p->number;
+ }
+   delete (p);
+   last->next = NULL;
+}
+
+/* writing a list on the output */
+void write(element *list)
+{
+  element *p;
+  cout<<endl;
+  p = list;
+  while (p!=NULL)
+  {
+    cout<< p->number<<"	";
+    p=p->next;
+  }
+  cout<<endl;
+}
+
+/* Gets a list and returns its length */
+int length (element *list)
+{
+   element *p;
+   int count=0;
+   p=list;
+   while (p!=NULL)
+   {
+     count++;
+     p = p->next;
+   }
+   return count;
+}
+
+/*Gets an element and returns its positon in the list. If the element*/
+/*is not in the list, returns 0 */
+
+int position(element *list,int num)
+{
+  element *p;
+  int i=1;
+  for (p=list;p!=NULL;p=p->next)
+  {
+    if ((p->number)==num)
+    return i;
+    i++;
+  }
+  return 0;
+}
+
+/*Gets a number and removes the element that stays in this position */
+void remove(element *&list,int position)
+{
+  element *before,*p;
+  if (position==1)
+  {
+    before=list;
+    list = list->next;
+    delete (before);
+  }
+  else
+  {
+    before = ele (list,position-1);
+    if (before!=NULL)
+    {
+      p = before->next;
+      before->next = p->next;
+      delete (p);
+    }
+  }
+}
+
+/* Insert a new element to be the i-th element of the list */
+/* the function uses the function add*/
+void insert(element *&list,int new_num,int position)
+{
+  element *p;
+  if (position==1)
+  add(new_num,list,NULL);
+  else
+  {
+    p = ele(list,position-1);
+    add(new_num,list,p);
+  }
+}
+
+/* Gets a position in the list and returns a pointer to the element*/
+/* in this position*/
+element *ele(element *list,int position)
+{
+  element *p=list;
+  int i;
+  for (i=1;i<position;i++)
+  {
+     if (p==NULL)
+     return p;
+     p=p->next;
+  }
+  return p;
+}
+
+/* Add a new element after a given element.If the given element is NULL*/
+/* Add the new element to be the first element*/
+void add(int new_num,element *&list,element *this_el)
+{
+  element *p;
+  if (list==NULL)
+  {
+    list = new element;
+    list->number = new_num;
+    list->next = NULL;
+  }
+  else
+  {
+    p = new element;
+    p->number = new_num;
+    if (this_el==NULL)
+    {
+     p->next = list;
+     list = p;
+    }
+    else
+    {
+      p->next=this_el->next;
+      this_el->next = p;
+    }
+  }
+}